Abstract Details

Title Cognitive Decline Over 18 Months in Patients With Mild Cognitive Impairment or Dementia due to Alzheimer’s Disease

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) P2 - Poster Session 2 (5:30 PM-6:30 PM)

Poster/Presentation
Number 9-031

Objective

To determine the rate of cognitive decline within 18 months in biomarker-confirmed (Aβ+) MCI and AD patients compared with (Aβ-) healthy controls.

Background

Understanding the cognitive decline in mild cognitive impairment (MCI) due to Alzheimer’s disease (AD) and AD dementia while also identifying tools that are sensitive to these changes is critical to understanding the course of disease. Longitudinal trials utilizing more frequent assessments may reduce noise associated with day-to-day variance in cognitive performance and improve statistical models of disease progression in AD. In the Australian Imaging, Biomarkers & Lifestyle (AIBL) Study, a subgroup of participants enrolled (Rate of Change supplement) underwent PET neuroimaging for amyloid β (Aβ) and had frequent (n=10) cognitive assessments conducted over an 18-month period.

Design/Methods Aβ- healthy controls (HC) with no cognitive impairment (n=67), Ab+ MCI patients (n=16), and Ab+ AD dementia patients (n=15) had a series of high-frequency (n=10) cognitive assessments over 18 months. The cognitive battery comprised tests of attention and information processing speed (Detection, Identification), working memory (One-Back Task), episodic memory (One-Card Learning, International Shopping List Test [ISLT]), and long-term recall (ISLT Delayed Recall).

Results Over 18 months, MCI and AD participants showed a greater rate of decline on the ISLT Total score compared with HC’s (Cohen’s d HC-MCI=0.93, P<.001; HC-AD=0.74, P<.001). On the ISLT Delayed Recall, MCI but not AD participants showed significantly faster decline than HCs.(Cohen’s d HC-MCI=0.91, P<.001; HC-AD=0.51, P=.078). None of the other cognitive assessments utilized could distinguish rate of cognitive decline between HC and MCI or AD participants over 18 months.

Conclusions ISLT measures were sensitive to detecting cognitive decline over 18 months in Aβ+ MCI and AD patients compared with Aβ- healthy non-demented adults. These results support the centrality of episodic memory decline in early AD. They also suggest that high-frequency cognitive assessments may facilitate earlier detection of Aβ+ memory decline.

Authors/Disclosures
PRESENTER	No disclosure on file
Ellen Huang	No disclosure on file
	No disclosure on file
Paul Maruff, PhD (Cogstate)	Dr. Maruff has received personal compensation for serving as an employee of Cogstate .
	No disclosure on file
Elena Ratti, MD (Takeda)	Dr. Ratti has received personal compensation for serving as an employee of Takeda. Dr. Ratti has received personal compensation for serving as an employee of Biogen. Dr. Ratti has stock in Takeda. Dr. Ratti has stock in Biogen.

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